I went into full-blown Heroic BSOD mode while watching Clannad.
I have to stop watching after
and cried for a whole hour and a half before i could contain myself and continue watching and crying.
I think I spent the whole last half of the second season sobbing.
And yet it's one of the best anime ever, but you have to be a serious masochist to keep watching.
EVERY SINGLE TIME
I would pause, wail, and then keep going.